The “GestiC©” integrated circuit, also known as MGC3130 manufactured by the assignee of this application, is a highly sensitive capacitive sensing technology that can be used for three-dimensional touch-less gesture detection and tracking using a quasi-static alternating electric near field, for example around 100-200 kHz. Such a system usually uses a transmitting electrode receiving an alternating signal such as a sinusoidal or square wave signal to generate the electric field. A plurality of receiving electrodes are arranged, for example, above the transmitting electrode in a frame like fashion, and from received signals a three-dimensional position of an object can be reconstructed within an integrated circuit device through signal processing.
Human interface devices (HID) that use such an integrated circuit device require sensor electrodes that are often formed in layers of conductive material, e.g. stripes of copper of a printed circuit board layer (PCB). These electrodes are electrically connected to a detection unit in the integrated circuit. For a detection system a conventional electrode arrangement can be formed on a multi-layer printed circuit board, wherein the bottom layer is often in its entirety or a significant portion of it used as a transmitter and smaller receiving electrodes and compensation electrodes can be formed on the top layer. More than two layers can be provided to build an electrode which also may increase the manufacturing cost for such electrode arrangements.
The gesture detection unit's measurement value, among others, depends on the position of a target object (finger/hand) in the sensor electrode's vicinity which influences the capacitive coupling between electrode and target, yielding a target measurement signal depending on the distortion of the alternating electric field. The gestures are performed above a detection area without touching any area of the respective device. In addition, touch detection may also be required for performing/initiating certain functions of the device.
Flatness of the industrial design and manufacturing costs are driving projective capacitive touch displays in consumer and other industries. Today, an increasing number of touch panels in consumer display applications are single-layer electrode designs, which are easier to manufacturer, achieve higher yields, are thinner and of significant lower cost. Furthermore single layer designs may offer better optical characteristics (higher transparency). Today's two layer GestIC© electrode design is a barrier accessing such early mass volume markets with 3D hand position tracking and gesture recognition.